This article describes and analyses four experiences of Geographical Data Infrastructures, three of which are national (UK, Portugal and Finland), while one is a local initiative in theLuxembourg province of the Wallonia Region of Belgium. Given the differences in scale and scope of these projects, they are not strictly comparable. They provide, nevertheless, a usefulsnapshot of current practise in Europe. Moreover, the extent to which similar issues arise at both national and local levels, increases the value of this sharing of experience as local andcentral government agencies across Europe come under increasing pressure to open access to the information they hold. (EC Green Paper on Public Sector Information: a key resource forEurope: